Hi Happyfunball I sent you a link in a PM, have you seen it ?

Yes thanks.

Have you tried any sort of magnetic shielding?

Wrong. It can't "clearly drop" and I've seen it many times. Do you think this is the first SMOT we've seen here? The first time even that that design variant has been shown?

Go on, show it dropping, if you can, and repeating the cycle without outside help. I say you cannot.

Why not? What possible reason is there for not showing the complete cycle with the thing running along all by itself over and over?

What reason, other than the fact that it is physically impossible, I mean?

If you look at my pendulum that drops from 2 oclock and rises to noon you can see that
magnets and gravity can work together to assist each other. But in Elecar's setup he escapes via the switch where my pendulum was fastened to the axle and could not escape and repeat.

here http://www.youtube.com/watch?v=4FzK2XKQ-74

Oh and enough of the ego stuff please. I'm here to learn and don't have time to waste on
useless bickering.

Norman

Hi Elecar,

Excellent thread!

This reminds of a few years back when Greg Watson built the first SMOT and was offering it in kit form but never managed to send any kits out if I remember right. 
I am not sure if he did get it to loop, but I think he claimed he did.

What you have here is very interesting.
This evening I have been playing with some 10 x 13 x 10 x 1.5mm x 1m aluminium chanel and a 24mm steel ball bearing and a very large 6 x 4 x 1" ceramic 8 slab magnet.
I can see the effect where the ball is pulled up the incline and then falls back down again under gravity, the cycle then repeats, with the ball zipping up and down the track for around 30 seconds before it stops.
I tried it with the track sitting on top of the slab magnets long edge on so the N-S faces of magnet face out to the sides.
Not sure it this config would be good for your setup as the magnet is below the track.
I have been using Lego bricks to build the support for the tracks.

You are right about the null spot in the middle of the magnet array, this would make the logical exit point away from the magnet using the downward momentum to carry it away from the null point and back around to the start.
I think a key thing is to have one uniform magnet as any ripples in the field tend to spoil the effect.

I am still trying to figure out the best way of get the ball to use the exit track on its downward journey.
My thoughts are with 3 rails that come to a point, as the ball reaches its max position it falls onto the outer 2 rails then returns down the 1/3 section before swinging out and away from the magnetic field.

For material, brass would be a good choice for tracks too as it can also be soldered and is easy to get hold of from B&Q and places like that.

I would like to see your working prototype if that is possible.

Meggerman

Hi Bill, I did not use a bumper as such during my trials, what I did was attach a very slim wedge shaped piece of acrylic to the magnet side rail of the track to try and guide the ball, it did NOT work the resistance was enough to stop the ball and it was held where it was by the magnets.
Please look at the drawing, the rail circled is the critical rail. It must allow the ball to travel smoothly up the ramp and when the ball descends it must be positioned to guide it onto the exit. It does take a lot of playing with you can not have the rail sit too high where it impedes the ball traveling up but high enough that it will bias the ball rolling in reverse to the exit. although that is how I did it, I really do believe there are easier ways. Something else that is important is that you can not divert the ball just as it starts to reverse, you have to allow it at least a third of the straight section to gain enough momentum to exit. That is why I said you should do the tests because they will help you get the magnet positions correct. You will get an idea of how the ball reverses and how much space/length you need before the junction. Do not build your ramp with too steep an angle otherwise the magnets will have to be placed to close to the track and your ball will not escape the field.

Elecar,   Thank you for your reply. I think I understand about the reverse momentum.   
I am curious about how you keep your base level.  If sold as a Toy it may be difficult to get everything level for kids.   Also, you mentioned you used aluminum rods.  Did you space the rods like a train track or another method?
Bill

Elecar,   Thank you for your reply. I think I understand about the reverse momentum.   
I am curious about how you keep your base level.  If sold as a Toy it may be difficult to get everything level for kids.   Also, you mentioned you used aluminum rods.  Did you space the rods like a train track or another method?
Bill

Hi Bill, the base is just MDF, I would think more along the lines of executive desktop  toy/novelty the track is set up just like a marble race.

Hi Elecar,

I whipped up some simple tests with just the ramp.

I tried neo magnets since I have many of those on hand. Neo magnets are very strong and from my experiment did not allow the 2cm diameter steel ball to fall back down. The sphere moves up the ramp and just sticks to the side. I would need a larger sphere to get the fall away effect with neos.

With the few ceramic magnets I have they work much better. I get the effect of the ball rolling up a slight incline then rolling back. I see where the challenge is switching, because it still wants to stick to one side but decreases as it falls back.

I also tried with a smaller sphere 1cm diam, it will pull up faster but stick more. It didn't have enough mass to fall back.

The switch between magnetic and fall back to gravity is where the challenge lies in this design.

I attached a picture of the quick ramp tests. The rise isn't very big because I don't have enough ceramic magnets to create a strong enough pull. (3.2mm per flat Lego block so the end height for 3 flats+track 6.4mm= 16mm height at the end)

Hi DTB, I was not able to get the ball away from the field with neos, I have a large collection of magnets but ended up buying C8s which did the trick.
On your test ramp if  you add a ramp that feeds the ball into the magnetic ramp (like shown in my video) you will get the ball to travel further up the ramp even when the magnets are placed further away, you should find that your ball will not only just roll back, but will roll right out of the bottom of the magnetic ramp.

Hi Happyfunball, I have no idea if they would end up the same distance if the tracks continued on a level, but it does appear, at least to me that the ball taking the longer route is traveling faster at the exit ? I could be wrong.